The present invention relates to a cutting device for cutting the edge portion of a sheet bundle in which a plurality of sheets are stacked on top of one another, a finisher for finishing the sheet ejected from the image forming apparatus, on which an image has been formed, thereby creating a sheet bundle and cutting the edge portion of the sheet bundle, and a bookbinding system equipped with an image forming apparatus and the aforementioned finisher.
Heretofore, there has been provided a finisher equipped with a cutting device, that receives sheets on which images have been formed by an image forming apparatus such as a photocopier and printer, and binds the sheets by performing the processes of center-binding and center-folding, and then cuts and trims the edge portion of the sheet bundle bound in the form of a book.
In the cutting device described in the Unexamined Japanese Patent Application Publication No. 2005-40890 (Claim 15, FIG. 15), a sheet bundle is held in vertically or obliquely by a holding and rotating section for holding the sheet bundle, and is cut by sliding a rotating circular cutting blade from the lateral or upper oblique direction with respect to the sheet bundle. Then chips produced by the process of cutting are dropped into a dust box by rotating a paddle arranged nearby.
In the cutting device described in the Unexamined Japanese Patent Application Publication No. 2005-169598 (Paragraph 0080, FIG. 11), the edge of a sheet bundle is cut by back-and-forth motion of a rotating cutting blade, and the cutting device is provided with a rotating paddle for removing the chips being cut by a cutting blade away from the vicinity of the cutting blade.
The cutting device disclosed in the Unexamined Japanese Patent Application Publication No. 2005-342854 (Claim 1, FIG. 1), is provided with a scraper formed of an elastic thin plate, which is brought in elastic contact with an upper movable blade to remove the chips depositing onto the upper movable blade.
The paper cutting device disclosed in the Unexamined Japanese Patent Application Publication Nos. 2005-271175 (Paragraph 0027, FIG. 5), is provided with a descending paper holder and ascending cutter, and with a continuous cover attached on the blade surface of the cutter tip for removing paper chips.
In the cutting device disclosed in the Unexamined Japanese Patent Application Publication No. 2005-40890 (Claim 15, FIG. 15), a paddle comes into contact with chips formed during cutting sheet bundle held vertically or obliquely from above or from the side in the vicinity of the cutting blade, and the chips are removed in the direction away from the cutting blade. In this arrangement, minute chips attached to the cutting blade cannot be removed through direct contact with the cutting blade. after cutting, the chips depositing on the cutting blade will enter the apparatus.
In the cutting device disclosed in the Unexamined Japanese Patent Application Publication No. 2005-169598 (Paragraph 0080, FIG. 11), the sheet bundle is cut out from top down. To solve the problem of cutting failure due to the chips depositing on the bundle, paddles for removing the chips are installed on both the front and rear sides in the traveling direction of the disk-shaped cutting blade, which is similar to the case of the Unexamined Japanese Patent Application Publication No. 2005-40890. However, even if it is possible to remove the large-sized chips that can be brought into contact with the paddles, small-sized chips are not brought into contact with the paddles. These chips are easy to adhere to the side surface of the cutting blade. After cutting, the chips depositing on the cutting blade will enter the apparatus.
In the cutting device disclosed in the Unexamined Japanese Patent Application Publication Nos. 2005-342854 (Claim 1, FIG. 1), a scraper formed of an elastic thin plate comes into contact with the cutting blade to remove the chips depositing on the upper movable blade and to drop them under their own weight. Chips are removed when the cutting blade cuts sheet bundle from top down and moves upward. According to this arrangement, chips having been removed by the scraper drop onto the cut sheet bundle located below and are easy to be deposited on the blade surface. Thus, these chips together with the sheet bundle will be fed into the apparatus.
In the Unexamined Japanese Patent Application Publication No. 2005-40890, No. 2005-169598, or No. 2005-342854, the method of cutting the sheet bundle up from bottom is preferably used because chips fall easily under their own weight, in contrast to the method of cutting the sheet bundle from above or from the side.
The sheet cutting device disclosed in the Unexamined Japanese Patent Application Publication No. 2005-271175 (Paragraph 0027, FIG. 5), is based on the method of cutting up from bottom, and is provided with a descending paper holder and an ascending cutter. The chips having been cut slip down the chip falling cover extending continuously to the blade surface of the cutter tip, and the chips depositing on the cutter tip cannot be removed. Thus, chips deposit on various members of the cutting device or enter the apparatus. This will cause apparatus operation failure or suspension or conveyance failure of the sheet bundle SS.